These calculators help you put a number on your emissions before you decide what to cut and what to offset. Each one shows how it calculates, with a worked example and the sources for every factor, and none of them asks for an email address.
Which calculator do I need?
- Carbon footprint calculator. Four short steps (home, travel, food and shopping) give an estimate of your yearly footprint, your biggest sources and three actions that would cut it most. It compares your result with your country’s average.
- Flight emissions calculator. Choose two airports, the cabin class and the trip type to get the emissions per passenger, with or without non-CO₂ effects.
- Credits needed calculator. Turn tonnes of CO₂e into a number of carbon credits, with an optional buffer, and see an estimated cost at the latest published average prices.
The tools pass results on: the flight and footprint calculators link to the credits calculator with your tonnes filled in. You can also open the credits calculator directly if you already know your emissions, for example from a company report or a travel booking.
Where the numbers come from
Home energy, travel and flight factors come from the UK government’s 2026 greenhouse gas conversion factorsSource 1. Prices in the credits calculator come from our monthly price snapshot: Sylvera’s Q3 2026 data for the market average and the main forest typesSource 3, and Ecosystem Marketplace’s 2023 and 2024 average transaction prices for other credit typesSource 2. Each calculator page lists every factor it uses and links to the original source, so you can check the arithmetic yourself.
What to do with your result
Start with the biggest sources and cut what you can. Then, if you want to offset what remains, our guide to how to offset your emissions explains the steps, and how to offset a flight covers flights in detail. Before you buy credits, read how to verify carbon credits so you know how to check the retirement.